Subwoofer buzz

[Kalthanan]

I hooked up my sub yesterday, and it worked fine for a while. Of course, we are moving things around and unpacking and stuff. I did some moving around of my ht equipment and now every time I plug in the subwoofer it hums REALLY LOUDLY.

I did some searching online, and the most likely culprit is something being unshielded. I unplugged everything in the vicinity, and even turned off some stuff upstairs; anything I could think of that would be new. Still hums.

It hums with nothing hooked up except the power. I've tried a different power plug in the room too, but no luck.

Any ideas?

[Catweazel]

Talk bout coincidence, but I had exactly the same problem with my guitar amp/speaker. The amp was blowing fuses, after many conversations the speaker cable was suspected and I switched to an unshielded speaker cable to test. The speaker started humming with the unshielded cable but it didn't blow fuses. I am still mid way through replacing speaker cables and have not totally fixed it......

your guess about unshielded might be a good one -- perhaps the shielding has become damaged durng the move?

I also have a pet theory about static in rugs and air humidity as other possible causes - all of which should be eliminated by a good shielding system. Finally, you can get electrical noise if things are not grounded correctly - and the cause for this could be simple or complicated. In a brand new house, there could be many reasons.

[Larphey]

Do you have a voltage tester? The problem could be in a loose grounded (neutral) wire. That can cause the voltages to go wacky. Try it on a different circuit perhaps? Not a different plug in that room but make sure that it is on a circuit not attached to those outlets.

[Kalthanan]

perhaps the shielding has become damaged durng the move?
The thing is, it worked okay for a little while *in this house* until I moved some things around in the room, plugged in some new stuff, etc. But I unplugged all the new stuff to test it, and no luck. It hums even when it's the only thing on in the whole room.

Do you have a voltage tester? The problem could be in a loose grounded (neutral) wire. That can cause the voltages to go wacky. Try it on a different circuit perhaps? Not a different plug in that room but make sure that it is on a circuit not attached to those outlets.
I have a voltmeter, but I really know jack-all about using it. Hey look, the needle moved! Cool! That's about what I know.

I'll try it in some more plugs in different rooms. I can open it up, but I don't know enough about it to repair it if it's broken.

[Catweazel]

The thing is, it worked okay for a little while *in this house* until I moved some things around in the room, plugged in some new stuff, etc. But I unplugged all the new stuff to test it, and no luck. It hums even when it's the only thing on in the whole room.


Electrical noise is not bounded by walls (at least not much) so that it might not be something in the room that is now interfering.

As Larps says - try and find a completely different "electrical" position....different circuit (you can find one by quickly flippping your breakers on and off)....different "field" position (north wall instead of south, upstairs instead of down) to zero on on the likely culprit. Could be a ceiling fan in the floor below, a fridge motor in the next room, an electric (fluorescent) light ballast almost anywhere, all of which should probably be ruled out before assuming the unit itself has problems.

[Dreggo]

I haven't the slightest clue about all things electrical, but I will share this:

As a DJ, I had certain venues that would cause my speakers to hum despite many configurations and placement. My equipment was all professional grade with shielded cables. The conclusion that I finally accepted was that the power supply of the venue was somehow causing the inescapable hum. I called it the "kryptonite under the stage" to anyone whom asked.

It may very well be that you have inheirited the same.

[Gottikets]

Most likelly cause is Noise in your power. As much as it pains me to say this. Monster has a lot of surge type protectors that have noise filters. You could "Test" one by buying it and seeing if it will fix the problem, more then likely it will. Their most expensive one is 500, cheapest is around 80 I think. One thing to consider is if the power to your house is allways gonna be noisy you might wanna buy UPS for your computers to prevent serious problems down the road.

[Kharmen]

More ideas..

May be 60hz humm. You could also try running wires directly across the floor (hopefully away from the source of the noise). Unshielded wires may be the problem. Wires should cross power at 90 degree angles.

The amplifier may have also gone bad. They can exhibit a sound like a very loud motorboat when they go out.

:peng_juggle:

Off to class for me...